Chest Radiography

An early chest radiograph is obtained to confirm the diagnosis of CDH. Findings include loops of bowel in the chest, a mediastinal shift, a paucity of bowel gas in the abdomen, and the presence of the tip of a nasogastric tube in the thoracic stomach (see the image below). Repeated chest radiography may reveal a change in the intrathoracic gas pattern. Right-side lesions are difficult to differentiate from diaphragmatic eventration and lobar consolidation.

Radiograph of an infant with congenital diaphragmatic hernia. Note shift of the mediastinum to the right, air-filled bowel in the left chest, and the position of the orogastric tube.

In a study involving 18 neonates with CDH, Tanaka et al found the use of M-mode imaging to measure diastolic wall strain to be a useful method for evaluating the diastolic function of CDH patients.
[18]

In centers where fetal intervention and postnatal management protocols are determined by antenatal assessment of pulmonary hypoplasia, the lung-to-head ratio (LHR) and the lung-to-thorax transverse ratio (L/T) are calculated.

One definition of the LHR is the area of the contralateral lung (the product of the two longest perpendiculars) divided by the head circumference at the four-chamber view. Standardization of LHR measurements may lead to improved prediction of outcomes in neonates with isolated CDH.
[19] L/T is the ratio of the area of the contralateral lung to the area of the thorax at the four-chamber view on ultrasonography.
[20, 21]

Ultrasonography reveals polyhydramnios, an absent intra-abdominal gastric air bubble, mediastinal shift, and hydrops fetalis. Ultrasonography demonstrates the dynamic nature of the visceral herniation observed with congenital diaphragmatic hernia. The visceral hernia has moved in and out of the chest in several fetuses.

Philip Glick, MD, MBA Professor, Departments of Surgery, Pediatrics, and Gynecology and Obstetrics, Vice-Chairperson for Finance and Development, Department of Surgery, State University of New York at Buffalo